Predicting intentions not to "drink and drive" using an extended version of the theory of planned behaviour.

The aim of this study was to determine to what extent the theory of planned behaviour (TPB) extended with moral norm and descriptive norm is able to predict intentions not to drink and drive. We also wanted to examine whether different processes guide intentions among young drivers (35 years and below) versus drivers aged above 35 years, and women's versus men's intentions. Questionnaires were sent to a sample of 4000 people in Norway aged between 18 and 70 years, and were completed by 1025 respondents. Analyses were conducted among those who had a driver's licence and who reported drinking at least 1-2 times per year, resulting in a sample of 879 individuals (46.6% were men, 30.3% were 35 years and younger, M=43.9 years). The results showed that the TPB variables explained 10% of the variance in intentions in the sample as a whole, and that the extension variables added 2% to the explained variance after controlling for the impact of the TPB components. Perceived behavioural control was the strongest predictor of intentions (β=0.24, p<0.001), followed by descriptive norm (β=-0.12, p<0.001), attitude (β=0.09, p<0.01) and moral norm (β=0.08, p<0.05). Several group differences were found. The extended TPB model explained 16% and 5% of men's and women's intentions, respectively, and 26% and 9% of the variance in intentions among young and older drivers, respectively. The practical implications of these results for the development of interventions to encourage drivers not to drink and drive will be outlined.

[1]  Jacob Cohen.  Statistical Power Analysis for the Behavioral Sciences , 1969, The SAGE Encyclopedia of Research Design.

[2]  D. Parker,et al.  Extending the theory of planned behaviour: The role of personal norm , 1995 .

[3]  M. Conner,et al.  Social cognition models and health behaviour: A structured review , 2000 .

[4]  M. Zanna,et al.  Attitudes and Attitude Change , 1993 .

[5]  M. Becker,et al.  The Health Belief Model: A Decade Later , 1984, Health education quarterly.

[6]  I. Ajzen.  The theory of planned behavior , 1991 .

[7]  P. Sheeran,et al.  How confidently can we infer health beliefs from questionnaire responses , 1996 .

[8]  D. A. Kenny,et al.  The moderator-mediator variable distinction in social psychological research: conceptual, strategic, and statistical considerations. , 1986, Journal of personality and social psychology.

[9]  S G Stradling,et al.  Determinants of intention to commit driving violations. , 1992, Accident; analysis and prevention.

[10]  Derek R. Rutter,et al.  Predicting and understanding safety helmet use among schoolboy cyclists: A comparison of the theory of planned behaviour and the health belief model , 1998 .

[11]  Mark Conner,et al.  Predictive validity of the theory of planned behaviour: The role of questionnaire format and social desirability , 1999 .

[12]  T. Cook,et al.  Quasi-experimentation: Design & analysis issues for field settings , 1979 .

[13]  D E Berger,et al.  Legal and social control of alcohol-impaired driving in California: 1983-1994. , 1997, Journal of studies on alcohol.

[14]  I. Ajzen,et al.  Predicting dishonest actions using the theory of planned behavior , 1991 .

[15]  M. Conner,et al.  Can the Theory of Planned Behaviour mediate the effects of age, gender and multidimensional health locus of control? , 2002, British journal of health psychology.

[16]  P. Sheeran,et al.  Descriptive norms as an additional predictor in the theory of planned behaviour: A meta-analysis , 2003 .

[17]  Isabelle Marcil,et al.  Motivational factors underlying the intention to drink and drive in young male drivers , 2001 .

[18]  I. Ajzen.  Constructing a TpB Questionnaire: Conceptual and Methodological Considerations , 2002 .

[19]  R. Rogers.  Cognitive and physiological processes in fear appeals and attitude change: a revised theory of prote , 1983 .

[20]  John T. Cacioppo,et al.  Social psychophysiology : a sourcebook , 1983 .

[21]  M. Hogg,et al.  The theory of planned behaviour: self-identity, social identity and group norms. , 1999, The British journal of social psychology.

[22]  M. Conner,et al.  Efficacy of the Theory of Planned Behaviour: a meta-analytic review. , 2001, The British journal of social psychology.

[23]  K. Skullerud,et al.  [Of what significance are diseases, intoxication and suicide in fatal traffic accidents?]. , 2004, Tidsskrift for den Norske laegeforening : tidsskrift for praktisk medicin, ny raekke.

[24]  Douglas Eadie,et al.  Development and evaluation of a mass media Theory of Planned Behaviour intervention to reduce speeding. , 2004, Health education research.

[25]  M. Conner,et al.  Examining normative pressure in the theory of planned behaviour: Impact of gender and passengers on intentions to break the speed limit , 2003 .

[26]  M. Conner,et al.  Extending the Theory of Planned Behavior: A Review and Avenues for Further Research , 1998 .

[27]  Susanne Hempel,et al.  Effective Interventions for Speeding Motorists , 2006 .

[28]  James S. Baxter,et al.  Intention to commit driving violations: An application of the theory of planned behavior. , 1992 .

[29]  P. Sheeran.  Intention—Behavior Relations: A Conceptual and Empirical Review , 2002 .

[30]  P. Norman,et al.  Predicting adolescent pedestrians' road-crossing intentions: an application and extension of the Theory of Planned Behaviour. , 2003, Health education research.

[31]  H Gjerde,et al.  Incidence of alcohol and drugs in fatally injured car drivers in Norway. , 1993, Accident; analysis and prevention.

[32]  Emilio Moyano Díaz.  Theory of planned behavior and pedestrians' intentions to violate traffic regulations , 2002 .

[33]  D. O’Keefe.  Persuasion , 1990, The Handbook of Communication Skills.

[34]  A. Wu,et al.  Invulnerability and the intention to drink and drive: an application of the theory of planned behavior. , 2010, Accident; analysis and prevention.

[35]  Carl A. Kallgren,et al.  A focus theory of normative conduct: Recycling the concept of norms to reduce littering in public places. , 1990 .